"It is with very deep sadness that we confirm the tragic death of a member of our nursing staff, Jacintha Saldanha," the statement read.

"Jacintha has worked at the King Edward VII's Hospital for more than four years. She was an excellent nurse and well-respected and popular with all of her colleagues."

It continued: "We can confirm that Jacintha was recently the victim of a hoax call to the hospital. The hospital had been supporting her throughout this difficult time."

It is believed that Saldanha was neither suspended nor disciplined by the hospital over the hoax call she put through to another nurse.

A statement from St James's Palace read: "The Duke and Duchess of Cambridge are deeply saddened to learn of the death of Jacintha Saldanha.

"Their royal highnesses were looked after so wonderfully well at all times by everybody at King Edward VII hospital, and their thoughts and prayers are with Jacintha Saldanha's family, friends and colleagues at this very sad time."

John Lofthouse, chief executive at King Edward VII's Hospital, added: "Our thoughts and deepest sympathies at this time are with her family and friends. Everyone is shocked by the loss of a much loved and valued colleague."

Lord Glenarthur, chairman of King Edward VII's Hospital, said: "This is a tragic event. Jacintha was a first class nurse who cared diligently for hundreds of patients during her time with us. She will be greatly missed."

An initial Scotland Yard statement had read: "Police were called at approximately 9.25am on Friday, December 7, to a report of a woman found unconscious an address in Weymouth Street, W1.

"London Ambulance Service attended and the woman was pronounced dead at the scene. Inquiries are continuing to establish the circumstances of the incident. The death is not being treated as suspicious at this stage."